Apparatus for boring or drilling angular holes.



No. 724,422. PATENTED APR. 7, 1903.

R. BARTHOLOMAUS. APPARATUS FOR BORING OR DRILLING ANGULAR HOLES.

APPLIUATION FILED JUNE 26, 1902.v

no MODEL. 3 sums-sum 1.

' N2 .724,422. PATENTED APR. 7. 1903'.

' Rf BARTHOLOMAUS.

( APPARATUS FOR BORING 0R DRILLING ANGULAR HOLES. I

APPLICATION FILED JUNE ZB, 1902. N0 MODEL.- I 3 SHEETS-SHEET 2.

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PATENTED APR. 7, 1903.

R. BARTHOLOMAUS. APPARATUS FOR BORING 0R DRILLING ANGULA'R HOLES.

APPLICATION FILED JUNE 26, 1902.

a SHEETS-SHEET a.

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fies es A nvenfovf'a UNITED v STATES PATENT OFFICE. I

RUDOLF BARTHOLOMAUS, OF ALTDORF, NEAR NUREMBERG, GERMANY, ASSIGNOR TOWILHELMINE BARTHOLOMAUS, OF ALTDORF, NEAR NUREMBERG, GERMANY.

APPARATUS FOR BORING OR DRILLING ANGULAR HOLES.

SPECIFICATION forming part of Letters Patent N 0. 724,422, dated April7, 1903.

Application filed June 26,1902.

To all whom, it may concern:

Be it known that I, RUDOLF BARTHOLO- MliUs, mechanical engineer, asubject of the King of Bavaria, and a resident of No. 195 UntereBrauhausstrasse, Altdorf, near Nuremberg, Bavaria, Germany, haveinvented certain new and useful Improvements in Apparatus for BoringAngular Holes; and I do hereby declare the following to be a full,clear, and exact description'of the invention,

such as will enable others skilled in the art to circles are struck fromthe apices of an equilateral triangle as centers the figure formed bytheir common intersection will, if turned.

in a rigid square of such dimensions as to circumscribe said figure,form a true guide or shape for reproducing said square in the path ofany one of its vertices.

In the drawings, Figure 1 is a side elevation, partly in section, of myimproved device, showing it as applied to the spindle of an ordinaryboring or drilling machine. Fig.

2 is a detail in plan of the lower part of theapparatus shown in thepreceding figure. Figs. 3 and 4 are enlarged details in plan ofadjustable drill-guides for square and trian-' gular holes,respectively, showing the appropriate drill-shanks in cross-section.Fig. 5 is an enlarged detail in elevation of said guides. Fig. 6represents the apparatus in elevation as applied to a turning-lathe.Figs. 7 and 8 are enlarged details of the points of two differently-cutdrills. Fig. 9 is a longitudinal section through the lower end of adrill-spindle with frame a mounted thereupon, showing the drill-drivingmechanism. Fig. 10 is an elevation and part section taken at rightangles to View of Fig. 9 and showing details of the drill-drivingmechanism. Fig. 11 is a bottom plan View of the drill-driving mechanism.

A bail-shaped frame a, carrying between Serial No. 113,315. (No model.)

cheeks a at its lower ends the removable drillguide b, iscapable ofbeing secured to the spindle-bearing f of an ordinary drilling or boringmachine by means of pawls-cl engagin racks d on the up er strai ht faceof said frame and clamped as to their heel ends by hinged bolts 0 andnuts 0 against said hearing, the arrangement permitting the adaption todrilling-machines of various sizes. The spindle passes through a centralcore a in the frame.

To the spindle-head g a follower h is attached, preferably by screwingit thereon by means of the screws h. Into the under side of thisfollower a hardened-steel plate 'i is screwed to serve as a thrust-blockfor the borer k. "The latter is driven by a dog Z, secured to the borerZr itself and actuated by the spindle cross-head through its pins 71,depending on each side thereof, and since the borer continuously changesits position with regard to the axis of the spindle rollers m aremounted on said pins 11 to reduce friction and permit of the necessarylateral play. Thus the drill is free to follow the kinematic law whilebeing driven, and the thrust is taken by the hardened-steelthrust-plate,

while the dog is prevented from falling down by means of the flangedrollers working on the depending pins.

The borer 7c, shaped according to the kinematic law, slides in asuitableguide 1), formed by two or more checks 0, the sides of which areprovided with projections 0, Fig. 5, meshing together like teeth, sothat adjustment for any desired thickness of borer can be easilyeffected. This adjustment of the guidecheeks 0 can be effected byvarious auxiliary means-for instance, in the present case by means of aright and left screw-threaded spindle p. The guide may also bevertically movable in ways 1) (indicated by dotted lines ,in Fig. 1 andfull lines in Fig. 2) in the cheeks a, formed by the lower parallel endsof frame a, which are slotted for this purpose, to allow screw-bolts g,which carry the guide-cheeks o, to be moved up or down and to be held inposition by lock-nuts r, securing structure to the frame-cheeks.

To easily adjust the borer-guide for a certain size of hole, two plates8 are bolted to the under side of the guide I) and provided with points1, corresponding exactly with vertices of angle of guide in case ofsquare or With side and vertex in case of triangle or other such figure.On the work to be bored marks are made corresponding to the hole to bedrilled, and the points i are adjusted thereto by suitably moving thecheeks 0. The drilling of the hole will then take place conforming tosaid marks and according to the shape of the guide.

It is obvious that not only triangular and quadrangular holes, but alsopolygonal holes, can be bored with the aid of this apparatus, thecross-section of the drill in the latter case being given a polygonalform and the borer- .guide being altered accordingly. The exact shape ofthe drill-shank section can in each case be readily determined by theknown application of Cardans circles.

If the apparatus is to be applied to a turning-lathe, the follower h anddog Z are held' by the spindle 'v of the tail-stock and the work rotateswith the framed and the borer-guide b, which in this case are fastenedto the faceplate w, as shown in Fig. 6. The hinged bolts 0 and pawls dare not used in this form of attachment and are temporarily removed, theframe being held to the face-plate by any well-known means, such asordinary bolts used on lathes to carry work. It will be understood thatthis is one object in making the borer-guide readily removable'from theframe ato wit, in order that it may be reversed to bring the points 15against the work when cross-heads h and Z are used upon theadjustingspindle of a lathe and frame a is secured to the work-holderthereof. Owing to the fact that the borer simply abuts with its bluntend against the plate t', the inconvenient and lengthy operation offitting the borer-cone into the spindle-head is dispensed with.

Within certain limits the guides only require to be exchanged when theprofile of the vantage that grinding can be easily and rapidlyperformed.

What I claim, and desire to secure by Letters Patent, is-

1. In an apparatus for boring or drilling geometrically trueand-triangular, square or other polygonal holes the combination of aframe a, carrying an adjustably-arranged drill-guide 0, on the frame aslotted straight face, ratchet-teeth d on said straight face, a centralbore in the said face, and removable means for securing the said face tothe spindle of a drill-press.

*2. In an apparatus for boring or drilling angular holes, thecombination of a suitable frame, having a ratchet-toothed straight face;pawls engaging said ratchet, bolts pivoted to said pawls and passingthrough the adjacent part of the frame, and nuts engaging said bolts todraw down the heels of the pawls, whereby the frame may be secured tothe bearing of a drill-spindle.

3. In an apparatus for boring or drilling angular holes the frame a, theadj ustably and reversibly mounted polygonal drillguide I) carried bysaid frame, means for attaching the frame to a non-rotating member, thefollower h attached to the spindle-head g, pins 71 depending from saidfollower, the dog Z driving the drill and engaged and driven by the saidpins 17..

4. In an apparatus for boring or drilling angular holes, the combinationof a bailshaped frame having parallel cheeks at its lower con vergingends,a polygonal drill-guide adj ustably and detachably secured betweensaid checks, at spindle passing through the upper part of the frame, adetachable follower upon said spindle, a thrust-plate upon saidfollower, pins depending from the follower, a dog supported and drivenby said pins, a drill bearing against said thrust-plate, and secured anddriven. by said dog, said drill having a shank shaped in cross-sectionafter a modification of Oardans circles and adapted to coact with thesaid polygonal drill-guide to reproduce the similarly-polygonal path ofthe cutter.

5. In an apparatus for drilling angular holes, the combination with thedrill-guide and its cheeks 0, of plates 8 upon the under side thereof,provided with points 25 and carried, with said cheeks, whereby saidpoints serve to gage the size of the hole to be cut and the consequentadjustment of the cheeks.

In testimony whereof I affix my signature in presence of two witnesses.

' RUDOLF BARTnoLoMAUs.

Witnesses ALEX. WIELE, MAX SCHNEIDER.

